How Can I switch on and off the FET Pre-drivers?

[frankkong]

Hello,

      I want to  switch on and off the FET pre-drivers in order to reduce the current. My code is :

      if(PTT_PTT1)

         {

               PMFENCA_PWMENA = 0;

         }

          else

         {

               PMFENCA_PWMENA = 1;

          }

       if I clear the PMFENCA_PWMENA bit, the PMF can work well after set the PMFENCA_PWMENA bit.

I also find this in the RM,but I do not understand.

Any idea? 

Thanks!

[danielmartynek]

Hello,

You can mask and unmask the PWM channels using PMFCFG2_MSK[5:0] bits (please see Figure 15-41 RM rev. 2.11)

or disable the PWM generators by clearing PWMENx. That is up to you. 

Regards,
Daniel

[frankkong]

Thanks，Daniel

          If I clearing PWMENx, it will not work well when I set PWMENx again. There is no output on PWM channel.

           Now, I use the Timer0 interrupt to check the input square wave's duty. If the duty under 10% , I will close the motor. Meanwhile, I want to reduce stand-by current. If the duty up 15%, it will restart the motor.  I disable the GDU and PMF by   PMFENCA_PWMENA = 0; &GDUE_GFDE = 0. But when it restarts the motor ,there is no output on PWM channels. I enable the GDU and PWF when it restarts.

            What  can I do to disable the GDU and PMF if I don't use it? OR is there other way to reduce the stand-by current?

       Regards,

        Frank

[danielmartynek]

Hi Frank,

Can you check PMF and GDU fault registers before you enable the PWM generators again?

Thanks,

Daniel

[frankkong]

Hi Daniel,

 It doesn't work, I have check PMF adn GDU fault registers before I enable the PWM generators.

If I close the PMF / GDU, it will met GDUF = 0x21 ,Low VLS error. It returns 0, when I read GDUF and I can't clear it by GDUF = 0x21